arXiv subjects

Ioan Ghisoiu

Publications and source records attributed to Ioan Ghisoiu.

4 recordsLinked to original sources

arXiv2026

A new method for taming tensor sum-integrals

We report on the computation of a class of massless bosonic three-loop vacuum sum-integrals which are key building blocks for an evaluation of the Debye screening mass in hot QCD. Generalizing known techniques and introducing the concept of tensor reduction by dimensionality shifts (known to the zero-temperature community since the work of Tarasov in 1996) to finite temperature, we are able to treat hitherto unaccessible cases, which will allow us to finalize the long-term project of NNLO Debye mass evaluation.

hep-ph↗

arXiv2016

On high-order perturbative calculations at finite density

We discuss the prospects of performing high-order perturbative calculations in systems characterized by a vanishing temperature but finite density. In particular, we show that the determination of generic Feynman integrals containing fermionic chemical potentials can be reduced to the evaluation of three-dimensional phase space integrals over vacuum on-shell amplitudes - a result reminiscent of a previously proposed "naive real-time formalism" for vacuum diagrams. Applications of these rules are discussed in the context of the thermodynamics of cold and dense QCD, where it is argued that they facilitate an extension of the Equation of State of cold quark matter to higher perturbative orders.

hep-ph↗

arXiv2015

Debye screening mass of hot Yang-Mills theory to three-loop order

Building upon our earlier work, we compute a Debye mass of finite-temperature Yang-Mills theory to three-loop order. As an application, we determine a $g^7$ contribution to the thermodynamic pressure of hot QCD.

hep-ph↗

arXiv2012

Automated computation meets hot QCD

We give a short review on recent progress in the field of automated calculations in finite-temperature field theory, where integration-by-parts techniques have proven (almost) as useful as in the zero-temperature case. Furthermore, we provide one concrete example of an evaluation of a new three-loop master sum-integral that exhibits maximal divergence.

hep-ph↗